[Serusers] Pre-paid billing based upon SER

Hello, We're an ip-telephony operator in Sweden (www.wx3.se) , and we're looking for a platform which can help us undertake pre-paid billing of IP-telephony users. We have ourselves a processing platform for CDRs, but we don't have a registrar/proxy (rtp-handling) / voice messaging (potentially asterisk) which can make us support pre-paid services. What we need is a platform which can make a request (including call details) to a billing system, and continue the call set-up if the response is positive. As the call is ongoing, the system will periodically continue to ask the billing system if the call can continue (for another 60 secs, for example). If the call cannot continue any longer, the call will be "taken down". If a caller call, and there is not enough money on the account, the billing system will return with a negative response and a sip-url, the caller should be directed to the sip-url - which belongs to a voice-mail system, in which the appropriate response will be played. So my question is: Can SER - possibly with support of RTP Router : to have control of RTP-flow / call-redirection - support these requirements. Br, Terje Myhre <http://www.wx3.se/> www.wx3.se sip: <mailto:tem@wx3.se> tem(a)wx3.se tel +46 8 5250 7972